<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>demo 2-27</title>
	</head>
	<body>
	</body>
	<script>
		let a=Array.of()
		let b=Array.of(undefined)
		let c=Array.of(3)
		let d=Array.of(1,2,3)
		console.log(a);
		console.log(b);
		console.log(c);
		console.log(d);
	</script>
</html>